Current removable and exchangeable data storage media, for example magnetic tapes, hard discs and CDs, become more prone to the occurrence of error during read and write operations as their lifetime progresses. There is currently no means available to log accurately this increase in error rate and predict from it when a medium passes an acceptable threshold of reliability and becomes a potential systems failure point. Indeed, realising this, and that it is important, is a contributory part of the present invention.
Different data storage media handle errors in different ways. For example, CDs have high error rates but use high power error correction algorithms to compensate for this, whereas magnetic hard discs have very few errors and therefore use only low level error correction algorithms.
Whilst it is known to retain information relating to the usage of a data storage medium upon an advice section of the medium itself (e.g. tape usage information on the magnetic tape itself), repeated and frequent accessing of this section of media leads to wear and possible failure of this section of medium (as it is typically read/written to more than other parts of a tape). This early life failure can lead to the premature failure or retirement of the medium. Even when the section of the medium does not fail completely its increased unreliability with use is clearly undesirable. Additionally, the requirement to scan through media in order to locate the advice section means that this is a slow process not allowing instantaneous access to the usage data. The prior art usage data is stored on a tape, for example, not to create and manage a history log for tape quality management purposes, but rather to track where data came from—information that is retained for stored data-related purposes rather than for tape life-estimating purposes or quality of data establishing purposes.
In large tape libraries, in which there are typically tens of drives and thousands of media, and robot systems load media into the drives, it is virtually impossible to manage attrition of the media by manual means. This results in complete failure of media with its attendant loss of data.